1. Field of the Invention
The present invention relates to a stripping method for automotive resistance cable and other similar type of electrical cables, and to an electrical cable loosening device used for said stripping operation.
2. Description of the Prior Art
As shown in FIG. 2, a shielded cable P for use in automobiles has a tension member 1 made of an aramid or other polymer fiber, a core 2 formed around the tension member 1, a resistance wire 3 as a conductor wound in a spiral pattern around the core 2, an insulator 4 provided around the resistance wire 3, and a sheath 5 provided around the insulator 4.
In FIG. 3, the cable stripping operation of the cable P is schematically shown. To strip the end of the cable P, the sheath 5 and the insulator 4 are cut to have a cross section of circles by a stripping knife A, after which the stripping knife A is moved in the direction of the arrow to pull off the sheath 5 and the insulator 4 (forming the stripped part B indicated in imaginary lines).
In such a cable P as shown in FIG. 2, since the resistance wire 3 is spirally wound around the core 2, the inner surface of insulator 4 is thus interposed between the ridges of the spirally wound resistance wire 3. As a result, when the cable P is stripped of the insulator 4 and sheath 5, the insulator 4 is forced to move over and across the ridges of resistance wire 3. However, when the insulator 4 does not move or slide smoothly, the resistance wire 3 may be unwound or unravelled as shown in FIG. 4, or may be broken as shown in FIG. 5 resulting in the scraping of the surface of core 2. This is specifically caused by the tight engagement between the conductor 3 and the insulator 4, and equivalent damage may also occur when stripping other similar type of electrical cables.